Forgiveness means different things to different people. But in general, it involves an intentional decision to let go of resentment and anger.
The act that hurt or offended you might always be with you. But working on forgiveness can lessen that act's grip on you. It can help free you from the control of the person who harmed you. Sometimes, forgiveness might even lead to feelings of understanding, empathy and compassion for the one who hurt you.
Forgiveness doesn't mean forgetting or excusing the harm done to you. It also doesn't necessarily mean making up with the person who caused the harm. Forgiveness brings a kind of peace that allows you to focus on yourself and helps you go on with life.